Electric switch for flashing lighthouse-lanterns.



No. 706,577. Patented Aug. 12,1902.

F; MACKINTOSH.

ELECTRIC SWITCH FUR FLASHING LIGHTHOUSE LANTERNS.

(Application filed Jan. 9, 1899.)

(No Model.-)

,Wnnlsssas Z INVENTDR.

- I IT'ederick' MacKLntosI'x. I9

m5 Nomus PETERS cu. wum-uwo, WASHINGTON n c UNITED STATES PATENT OFFICE.

FREDERICK MACKINTOSII, OF SCHENECTADY, NEl/V YORK, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, A CORPORATION OF NEIV YORK.

ELECTRIC SWITCH FOR FLASHENG LlGHTHOUSE-LANTERNS.

SPECIFICATION forming part'of Letters Patent N 0. 706,577, dated August 12, 1902. 7 Application filed January 9, 1899. Serial No. 701,576. (No model- T whom/it y GOV/667W! device to be bolted to the dynamo and belted Be it known that I, FREDERICK MAOKIN- to or otherwise driven by the dynamo-engine, TOSH, a citizen of the United States, residing thuslocatingallthe moving electric apparatus at Schenectady, county of Schenectady, State together, where it may be conveniently -in- 55- of New York, have invented certain new and spected and kept in proper working order.

useful Improvements in Electric Switches for In general the switch consists of a ring mak- FlashingLighthouse-Lanterns,(Case No.831,) ing constant contact by the usual brush with of which the following is a specification. the lead from one terminal of the'generator My present invention relates to devices for and one or more other contact-rings, partly 60 I0 causing electric lightsto flash or burn incut away, with which other brushes register termittently at regularlyrrecurringintervals. to complete in proper sequence the circuits It is intended for and is particularly useful to the other generator-terminal.

inlighthouses,but maybe employed wherever The arrangement will be better understood necessary or desirable. from the accompanying drawings,which show 65 The main object of the invention is to proan. embodiment of my invention, Figure 1 vide a substantial and simple mechanism being a diagram of the circuits, Fig. 2 being making the circuit changes in the order and a side elevation, and Fig. 3 a plan of the with the speed chosen with regularity and switch mechanism. without liability to derangement and keeping I will first describe Figs. 2 and 3. In these 70 substantially a constant load upon the genfigures,A is the frame of the device,-which erator. may be secured to any suitable support by It iswell known that sudden changes of the the bolts a a. The angle at which the frame load on a generator are apt to produce violent shall stand is determined by the position of sparking. Theload inlighthouse illumination the set-screws Q Q, which allow the device to 75 is generally small, the larger part of whatever he applied to the sloping end of a dynamocurrent is generated'being consumed in the frame. In the frame A are journaled four lantern. The capacity of the generator there shafts B B B B in suitable bearings A, fore is usually only moderate. Under these 850. The shaft B carries a pulley D, driven conditions the percentage variation when the at any suitable speed and in proper direction 80 3o circuit is opened to extinguish the lightis very by the belt E. The pulley is geared to the large, ranging practically} from zero to full shaft I? through the gears CC C These load, and vice versa, at each circuit change. gears are inclosedin a suitable casing C, and To avoid this difficulty, I provide an artificial it is manifest that by changing the gear relaload arranged to take a current substantially tion the speed of the switch may be changed 8 5 equal to that of the lantern and a switchfor without changing that of the driving power. making theproper circuit changes. The 0011- The gear C is carried by an arm 0, pivoted at tacts of the switch are arranged with an over- This arm is extended and slotted at O. lapin order to insure that one circuit is closed A screw 0 carried by an extension 0 from before the other is opened. The artificial the gear-case C and by the frame A, serves to 0 40 load which I find most convenient is an ordilock the arm 0? in any desired position and nary non-inductive resistance; butobviously permits the gear C to be shifted to accomany translating or current-consuming device modate itself to any change in the relative may be used. diameter of the gears C 0 This permits To accomplish the objects here brieflyindithe speed of the shaft 13 to be adjusted at 5 cated, I provide an improved switch having will. Upon the shaft B is a bevel-wheel F, continuous rotary movement, with connecmeshing with a similar wheel F on the shaft tions and fixed contacts such that the circuit 13 A worm G 011 the latter shaft drives the changes desired are made in proper order. Worm-wheel G on the shaft B turning that Theswitch is driven byany convenient motor shaft and with it the moving parts of the 10:

go at the speed chosen either through gearing or switch. The latter consists of three moving otherwise. In practice I have arranged the contacts, one of which, H, is a complete circle or collector-ring, and with it constant contact is made. The other two are snail-cams ll I1 With these the brushes K K K register, and as the latter make and break contact the lights are kindled and extinguished. K is a rubber stop. This or a similar form of cam contact is desirable because it permits the brushes to snap in breaking contact, yet the circuit is completed with an easy action, giving a gradual]y-increasing pressure until the contact is quite firm. The arrange ment of the contacts is such that one of the brushes K K is always engaged before the other breaks contact. The brushes K, 850., are forced against the cams by the springs I l 1 which also act as current-carriers, the

main pressure, however, being supplied by the springs L, &c., acting upon the hell-crank levers 7;, (he, The three rotating contacts are cross-connected, the circuit being as shown in Fig. 1. Here N is the generator; M, the lamp or lamps. R is the resistance, substantially equivalent to the effective resistance of the load or lights M, being substituted for it by the revolution of the switch, so that the generator never works on open circuit. The arrangement of the switch is such that the circuit is never broken at the lights until the resistance is substituted, and vice versa. The circuit is from the plusbrush of the generator to the brush K, then to the ring H, to the contact H or H, as the case might be, then back to the generator through the lamps M or the resistance R or m omeutarily through both. The adjustment should be such that the two circuits are in multiple for a short time only; otherwise the load on the generator will be subject to the variation which it is the object of the invention to avoid. In a particular apparatus built by me I have found that the ammeter shows twenty-four amperes when the lantern is lighted and twenty-ion r am peres when the resistance alone is in circuit and rises to thirty amperes during the instant of change. This does not cause objectionable action in the generator.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. A switch comprising a plurality of relatively rotary contacts, a drive-shaft, a geartrain connecting the same with the rotary switch element, and an adjustable journal for one of the gear-wheels to permit changeable gearing to vary the rate of change in the control-circuit.

2. A switch comprising a rotary contact, a springbrush bearing thereon, an offset at the end of the contact to permit the brush to snap out of engagement, and a cushion of yielding material on the rotary contact to arrest the snapping movement of the brush.

In testimony whereof I have hereunto set my hand this 5th day of January, 1899.

FREDERICK MACKINTOSTI. Witnesses:

B. B. HULL, M. H. EMERSON. 

